Redmine

While adding comments to the ticket am getting internal server error:

ActiveRecord::StatementInvalid (Mysql2::Error: Incorrect string value: '\xF0\x9F\x91\x8D\x0D\x0A...' for column 'notes' at row 1: INSERT INTO `journals`

I tired changing the charset from utf8 to utf8mb4 for journals table but it doesn't seems to help.

Can anyone suggest a walk through for this issue.

My Environment

Environment:
  Redmine version                3.3.0.stable
  Ruby version                   2.3.1-p112 (2016-04-26) [x86_64-linux]
  Rails version                  4.2.6
  Environment                    production
  Database adapter               Mysql2
SCM:
  Subversion                     1.7.14
  Git                            1.8.3.1
  Filesystem                     
Redmine plugins:
  issue_charts                   1.3.0
  periodictask                   3.1.1
  redmine_checklists             3.1.3
  redmine_email_fetcher          0.3.1
  redmine_helpdesk               0.0.15
  redmine_issue_history          1.0.0
  redmine_omniauth_google        0.0.1
  simple_author_change           0.1.2